Our objective is to define more clearly the role of the genital mycoplasmas (M. hominis and the T-mycoplasmas) in venereally transmitted conditions. Non-gonococcal pelvic inflammatory disease will be studied using microbiological and serological techniques in the setting of a therapeutic trial of agents with and without in vitro activity against the genital mycoplasmas. Sexually transmitted pharyngeal infections will be studied in an attempt to define the relative contribution of the genital mycoplasmas and N. gonorrheae to the symptomatic pharyngitis seen in patients who have had oral-genital contact. The microbiological flora of Bartholin's gland abscesses will be studied. To avoid contamination by vaginal organisms, aspirates of intact abscesses will be obtained and cultured for aerobic and anaerobic bacteria and for mycoplasmas. A critical appraisal of the role of the T-mycoplasmas in non-gonococcal urethritis (NGU) will be undertaken. We have shown that sexual experience is a major determinant of colonization with the genital mycoplasmas. As none of the reported studies of colonization with T-mycoplasmas in patients with NGU have controlled for this variable, we will compare the rates of colonization with T-mycoplasmas among patients with NGU with colonization rates among men with gonorrhea and among normal men of similar sexual experience.